Method and Device for Producing a Link on a Drive-Shaft of a Motor Vehicle

ABSTRACT

The invention relates to a method and device for producing a torque-transmitting link on a drive shaft of a motor vehicle between two rotationally symmetrical components in the joint area, particularly the outer part ( 22 ) of a joint ( 18 ) of a drive shaft and a flange part ( 16 ) of a gearshaft, wherein said components are joined to each other by means of several screws ( 24 ) which are distributed in a peripheral direction. The screws cross through annular bearing surfaces ( 16   a   , 22   a ) of the components and an annular centering collar ( 16   c ) is formed on one component, encompassing the outer periphery of the other component in a loose fit. In order to obtain a productively advantageous and simple-to-mount link, a defined remaining balance error of at least one of the components is determined and peripherally marked, the component is fixed in a de-axised manner with respect to the other component according to the terms of the loose fit, and the remaining balance error is essentially compensated. Preferably, the annular bearing surface ( 16   a   , 22   a ) of one or two components is recessed at least in the region of the screws ( 24 ) in a radially outward manner as far as the centering collar ( 16   c ) in order to produce the defined de-axised effect.

The invention relates to a method for producing a link on a drive-shaft of a vehicle and transmitting torque, as specified in the preamble of claim 1, and to a device especially well-suited for this purpose.

A connection of rotating parts such as this is described, for example, in EP 0 671 568 B1 on the basis of a drive connection between a crankshaft of a motor vehicle and a gear unit. In order to achieve precise rotation of the crankshaft (or other drive shaft) in relation to the flanged portion of the gear unit it is proposed that the connection between the outer articulated part and the flange component be configured with a force-fitted centering collar. While this does ensure assembly of the connection free of play, production with very small tolerances is required. Relatively high insertion or removal moments may also occur during assembly of the connection. In addition, any residual imbalances which may be present on the individual structural components may not be counterbalanced.

The object of the invention is to propose a process for production of a generic connection which is more favorable from the production and functional viewpoints and which permits greater simplicity of assembly. A preferred device for conduct of the process is also presented.

The object of the invention as claimed is attained by the characteristic features as set forth in claim 1. Advantageous developments of the invention and a preferred device for production of the connection are described in the other claims.

It is claimed for the invention that a specific residual imbalance of at least one of the structural components is determined and marked on the circumference and that the structural component, offset, is fastened to the other structural component in such a way that the residual imbalance with the concentricity error is essentially offset. This results initially in simpler production, since the structural components may be produced within the clearance fit. In the case of the balancing processes of the components necessarily required a specific residual imbalance, the position of which is marked, may be accepted. In this instance it is made certain during assembly that the offsetting of one structural component in relation to another generally occurring during clearance fitting is achieved by compensation of the offsetting by the residual imbalance of the structural component or components.

As a further development of the invention a specific residual imbalance of both structural components may be determined and marked, the markings being overlapped at least more or less during assembly. This increases the quietness of the components in the area of connection and simplifies assembly or coordination of the components.

In the process the markings of the residual imbalances of the two components may be applied so as to be displaced by the same angular area clockwise and counterclockwise. The two residual imbalances of the components with the specific offsetting or the dynamic imbalance thus form a circulating triangle with free mass moments equaling zero in the most favorable case. The markings of the two components may by preference each be displaced 60 degrees in relation to the imbalance position and thus by 120 degrees in relation to each other and to the offset.

In addition, the annular contact surfaces of the components may be designed so that a specific offsetting of the components in relation to each other is effected during assembly. This ensures targeted offsetting accompanied by assembly easy to execute.

A radially external area of the annular contact surfaces of the components may in the process be axially reset so that the offsetting in question is effected when the bolt positioned closest to the markings is tightened. This measure as well greatly simplifies assembly and ensures the structurally intended position of the offset to the marked residual imbalances of the components.

In the preferred device for producing the connection it is proposed to configure the annular contact surface of one or both structural components reset at least in the area of the bolts and radially to the outside to the centering collar. This measure may be accomplished by simple production means and, when one of the bolts of the connection is tightened on one side, effects tilting of the component to be fastened to a specific offsetting inside the centering collar.

The annular contact surface of a component may be for this purpose be configured to be conical, but it is proposed by preference that the contact surface be configured to be stepped in cross-section, with an annular recess extending radially outward to the centering collar. The centering collar may by preference be mounted on the flange component.

In addition, a disk defining the recess in question may be positioned radially inside the bolts, by preference between the components or their contact surfaces. This results in simplified production, in which the recess is obtained automatically by introduction of the disk in question.

In addition, for the sake of simplicity of effecting a sealing function, the disk may have a sealing ring on its outer circumference adjacent to the contact surfaces.

Lastly, the disk may be configured to be plate-shaped as a cap which terminates the joint as the one component in the axial direction toward the flange component.

An exemplary embodiment of the invention will be described in detail in what follows. In the schematic drawing

FIG. 1 illustrates, as a longitudinal section, a connection transmitting torque between a flange component of a gear unit and the outer joint part of a crankshaft in motor vehicles,

FIG. 2 an enlarged section in the joining area of the connection shown in FIG. 1, and

FIG. 3 the joining area shown in FIG. 2, illustrating offsetting of the outer joint part in relation to the flange component during assembly.

In FIG. 1 10 designates only a section of a differential gear in the housing 12 of which an input shaft 14 is mounted so as to be rotatable. A rotation-symmetric component, a flange component 16, is fastened on the input shaft 14.

Another flange component, joint 18, of a drive shaft 20, only a section of which is illustrated, is connected to the flange component 16 in a manner yet to be described so as to transmit torque.

For this purpose the annular outer joint part 22 of the joint 18 (in this instance a homokinetic synchronizing joint of customary commercially available design) is uniformly connected by means of six bolts 24 uniformly distributed over the external circumference of this joint to the flange component 16, the bolts 24 (also see FIG. 2) extending through annular contact surfaces 16 a and/or 22 a in the joining area (=radial plane of separation between the flange component 16 and the outer joint part 22). Appropriate through bores 22 b are provided in the outer joint part 22 and appropriate threaded bores 16 b in the flange component 16. The six bolts 24 are positioned in a uniform bolt-hole circle d₁.

A centering collar 16 c projecting axially beyond the contact surface 16 a is formed on the flange component 16 for the purpose of centering the outer joint part 22 in relation to the flange component 16. The outer diameter of the outer joint part 22 and the internal diameter of the centering collar 16 c are from the viewpoint of dimension designed as clearance fit with a relatively large tolerance band, that is, the component is compressible for ease of assembly.

In addition, an annular steel disk 26 of specific strength having a sealing ring 28 of specific strength vulcanized on its external circumference has been added between the contact surface 16 a of the flange component 16 and the contact surface 22 a of the outer joint part 22 (see upper half of FIG. 1 and FIG. 2). The rotation-symmetric disk 26 with sealing ring 28 has been designed so that it is positioned by its external circumference inside the circular opening d₁ and inside the bolts 24 (external disk diameter=circular opening diameter d₁ minus bolt diameter). The result is a stepped course of the contact surface 16 a, which is suitably reset radially outside the disk 26 with sealing ring 28 to centering collar 16 c or forms an annular recess 16 d.

The recess 16 d may also be worked directly into the contact surface 16 a of the flange component 16 or the contact surface 22 a of the outer joint part 22. Optionally the contact surface 16 a and/or the contact surface 22 a may be configured to be slightly tapered rather than stepped.

As is to be seen in the lower half of the drawing in FIG. 1, the disk 26 may also be produced in a closed configuration as a plate-shaped cap 26′ and the joint 18 thus suitably encapsulated.

In addition, the annular disk 26 or the cap 26′ may be held centered on an annular shoulder 16 e worked into the contact surface 16 a or 22 a (FIG. 1). The annular shoulder 16 e then encloses the disk 26 axially to a distance which is smaller than the thickness of the disk 26 or cap 26′.

The following process is carried out in production of the connection described:

First the input shaft 12 is balanced with the flange component 14 in a suitable device (not shown) and any specific residual imbalance is provided with a marking (such as a colored dot or an impression on the external circumference of the flange component 16). However, the marking (not shown) is displaced 60 degrees clockwise and applied at the position of the residual imbalance.

The drive shaft 20 is similarly counterbalanced with the joint 18 and the specific residual imbalance is marked on the external circumference of the outer joint part 22. However, the marking is applied counterclockwise after displacement through 60 degrees over the circumference.

If the two markings are now made to overlap in assembly of the connection, the residual imbalances are displaced 120 degrees in relation to each other.

The six bolts 24 are then inserted loosely into the flange component 16 and then the bolt 24 positioned next to the markings is tightened by a specific torque. This tightening of a bolt 24 on one side, in conjunction with the configuration described in the foregoing of the contact surface 16 a with the recess 16 d, effects tilting of the outer joint part 22 (shown in exaggerated form by dashed lines in FIG. 3) in relation to the flange component 16, as a result of which the outer joint part 22 is positioned on the centering collar 16 c or intentionally offset from it, as a result of the telescopic guiding in the centering collar 16 c at the point diametrically opposite the tightened bolt 24 or its circumferential area.

If the other bolts 24 are now tightened, the outer joint part 22, as experiments have shown, remains in the intentionally offset position, which as a triangle is opposite the position of the two residual imbalances, that is, diametrically opposite the markings. The dynamic imbalance resulting from offsetting of the joint 18 and the drive shaft 20 at least essentially equals the residual imbalances of the input shaft 14 and flange component 16 and the joint 18 and drive shaft 20.

The invention is not restricted to the exemplary embodiment described. Thus, only one residual imbalance may be determined and marked on the flange component 16 or the joint 18. The marking is then positioned exactly, that is, with no displacement, on the residual imbalance, which is then followed by a diametrically opposite offsetting of the outer joint part 22 from the flange component 16 as described in the foregoing. Optionally the threaded bores 16 b of the flange component 16 and/or the through bores 22 b of the outer joint part 22 may be worked in only after balancing and/or determination of the residual imbalances in question, it then being possible to bring a threaded bore 16 b or a through bore 22 b into axial alignment with the marking in question for the residual imbalance.

The connection as described may also be used on other rotation-symmetrical components or drive connection. 

1. A method for producing a link of two structural components rotation-symmetrical in the joining area on a drive shaft of a motor vehicle, a connection transmitting torque in particular to the outer joint part of a joint of a drive shaft and a flange component of a gear shaft, such structural components being bolted to each other by means of a plurality of bolts in the circumferential direction, the bolts extending through annular contact surfaces of the structural components and an annular centering collar being formed on one structural component, such collar surrounding the external circumference of the other structural component in clearance fitting, wherein a specific residual imbalance of at least one of the structural components is determined and marked on the circumference side and in that the structural component is fastened to the other structural component within the framework of the clearance fit, in such a way that the residual balance is essentially offset.
 2. The process as specified in claim 1, wherein a specific residual imbalance of both structural components is determined and wherein the markings are caused in assembly essentially to overlap.
 3. The process as specified in claim 1, wherein the markings of the residual imbalances of the two structural components are applied after having been moved through the same angular area clockwise and counterclockwise in relation to the respective imbalance position.
 4. The process as specified in claim 3, wherein the markings of the two structural components are in each instance displaced 60 degrees in relation to the imbalance position.
 5. The process as specified claim 1, wherein the annular contact surfaces of the structural components are configured in such a way that, when one of the bolts is tightened on one side in assembly, a specific offsetting of the structural components in relation to each other is generated.
 6. The process as specified in claim 5, wherein an area of the annular contact surfaces of the structural components positioned radially outward is configured to be axially reset in such a way that the offset in question is generated on tightening of the bolt positioned closest to the markings.
 7. A device for production of the connection as specified in claim 1, wherein the annular contact surface of one or both structural components is configured so as to be reset radially outward at least in the area of the bolts and radially outward as far as the centering collar.
 8. The device for production of the connection as specified in claim 7, wherein the annular contact surface of a structural component is configured to be stepped as viewed in cross-section, with an annular recess extending radially outward to the centering collar.
 9. The device for production of the connection as specified in claim 1, wherein the centering collar is mounted on the flange component.
 10. The device for production of the connection as specified in claim 1, wherein a disk which defines the recess referred to and is positioned radially within the bolts is added between the components or their contact surfaces.
 11. The device for production of the connection as specified in claim 10, wherein the disk carries on its external circumference a sealing ring adjacent to the contact surfaces.
 12. The device for production of the connection as specified in claim 9, wherein the disk, in the shape of a plate, is configured as a cap which terminates the joint as the one component extending axially to the flange component.
 13. A device comprising: a link between two structural components rotation-symmetrical in the joining area on a drive shaft of a motor vehicle, a connection transmitting torque to the outer joint part of a joint of a drive shaft and a flange component of a gear shaft, the structural components are bolted to each other by a plurality of bolts in the circumferential direction, the bolts extending through annular contact surfaces of the structural components; an annular centering collar on one structural component, such collar surrounding the external circumference of the other structural component in clearance fitting, wherein a specific residual imbalance of at least one of the structural components is determined and marked on the circumference side and in that the structural component is fastened to the other structural component within the framework of the clearance fit, in such a way that the residual balance is essentially offset. 